Wireless communications span a number of individualized cellular networks throughout various parts of the world. Combined, these networks service over one billion subscribers. With the development of modern wireless technology, wireless communications have evolved from first generation (1G) networks, including Advanced Mobile Phone System (AMPS) and European Total Access Communication System (ETACS), to 2G networks, including United States Digital Cellular (USDC), General Packet Radio Service (GPRS) and Global Systems for Mobile (GSM), and 3G networks, including Code Division Multiple Access (CDMA 2000) and Universal Mobile Telecommunications System (UMTS). More recently, industry trends are moving toward 4G networks, including Worldwide Interoperability for Microwave Access (WiMAX) and Long Term Evolution (LTE).
As mobile wireless device become equipped to operate within modern 4G networks, antennas of such devices will be required to operate over associated frequency bands.
Moreover, with continuous evolution of wireless networks, subscriber regions are being developed with a priority aimed at advancing high-demand regions. Thus, all over the world a variety of networks exist with different operating requirements among individual regions.
This disparity in technologies between networks gives rise to a number of problems, including: (i) manufacturer's being required to design different internal antenna systems to adapt a particular device for operation within a desired subscriber region or associated technology; and (ii) subscriber devices being limited to operation within a particular subscriber region or associated technology such that subscribers may not use a device across multiple networks.
More recently, antenna systems have been provided for use within multiple subscriber regions and various wireless platforms. These wide band antennas generally utilize switches and active tuning components, such as variable capacitors, for tuning the associated antenna frequency for operation among the various bands.